unlock: Resolve hostname with hard-coded server

This is required after power outages when unlocking the server that does
dns in the network.

flake.nix

@@ -120,7 +120,11 @@
                   ssh \
                       ${lib.optionalString unlockOverV4 "-4"} \
                       -p 2222 \
-                      "root@${targetHost}" \
+                      "root@$(${pkgs.dnsutils}/bin/dig \
+                          +short \
+                          @${if unlockOverV4 then "8.8.8.8" else "2001:4860:4860::8888"} \
+                          ${targetHost} \
+                          ${if unlockOverV4 then "A" else "AAAA"})" \
                       "cat > /crypt-ramfs/passphrase" < <(pass "devices/${hostname}/luks")
                 '')
               self.nixosConfigurations);